(a) Field of the Invention
The present invention relates to a planetary gear set for an automatic transmission of a vehicle. More particularly, the present invention relates to a planetary gear set for an automatic transmission of a vehicle where a sealing element is provided so as to close a passageway connecting a sun gear lubrication path and a pinion gear lubrication path.
(b) Description of the Related Art
In a conventional planetary gear set of an automatic transmission, the lubrication oil for lubricating a needle bearing of a pinion gear is supplied to the needle bearing through a thrust bearing, which assists rotation of the sun gear. Therefore, since the lubrication oil is heated by the thrust bearing before being supplied to the needle bearing, the lubrication oil cannot sufficiently assist the rotation of the thrust bearing.
The above information disclosed in this background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.